Prosthetic device with antibiotics

ABSTRACT

Prosthetic device suitable for being implanted in a bone or joint site of the human body, including a prosthetic body, wherein the prosthetic device includes or can be added with antibiotic or a medical substance.

TECHNICAL FIELD OF THE INVENTION

The present invention regards a prosthetic device suitable for beingimplanted at a bone or a joint of the human body, wherein saidprosthetic device is an antibiotic-loaded prosthetic device.

In particular, such prosthetic device is capable of eluting or diffusingan antibiotic substance in order to prevent the onset of an infection orcure an infection underway.

DESCRIPTION OF RELATED ART

It is known that the prostheses implanted within the human body can besubjected to infections.

If this should occur, the infected prosthesis must in fact be removedfrom the implant site and, before the implant of a new prosthesis, it isnecessary to eradicate the infection. During such step, spacer devicesare normally employed in order to maintain substantially unchanged theshape of the bone site or of the joint site in which the new prosthesiswill be implanted, simultaneously releasing substances capable oftreating the infection.

Such procedure is known as “two-stage treatment” for the removal of aninfected prosthesis and the implant of a new prosthesis.

Nevertheless, sometimes, when the bone conditions allow, the surgeondecides to not carry out such procedure in two stages, but rather toapply a one stage treatment according to which, after having removed theinfected prosthesis and carried out the “cleaning” of the surgical site,the new prosthesis is immediately inserted into the surgical site,without having first used a spacer device for treating the infection.

In such case, the new prosthesis can be fixed to the bone of the patientwith bone cement, e.g. antibiotic bone cement, or it can also onlyinserted in the bone, in accordance with the specific situations. Whenthe prosthesis is inserted in the bone without the use of bone cement,it is more easily removable in case of onset of a new infection.Naturally, if the bone conditions are quite compromised, the use of thebone cement for fixing the new prosthesis is substantially required.

Surgeons who decide to use the “one stage” therapy trust in the factthat the cleaning or renewal of the bone and the systemic antibiotictherapy are sufficient for treating the infection underway or forpreventing the onset of a new infection. Nevertheless, from studiescarried out, it is seen that in this case the reinfection can occur evenif in a small percentage, which is different from what occurs with thetwo stage treatment where the onset of a new infection is an extremelyrare occurrence.

Gels or similar substances are available on the market that are capableof being applied, for example swabbed, on the outer surface of aprosthesis before the implant thereof. Such procedure can be appliedboth on a first insertion prostheses and on revision prostheses, i.e.implanted following the explant of a first insertion prosthesis.

Such gels or substances, while being antibiotic-loaded, are neverthelessineffective against bacteria since the contact time with the bacteriathemselves is overly reduced, in order to cause the death thereof.Usually, in fact, such substances are used to prevent bacteria, e.g.bacteria present in the outside environment, from being present orsettling on the outer surface of the prosthesis, thus preventing thesame from entering into the surgical site, even if they are notspecifically able to eliminate the bacteria present within the bone orjoint site of the implant.

There is therefore the need for the surgeon to be able to implantprosthetic devices, both first implant and revision prosthetic devices,capable of preventing the onset of infections or capable of curing thosepresent.

SUMMARY OF THE INVENTION

The task of the present invention is to improve the state of the priorart.

In the scope of such technical task, one object of the present inventionis to provide a prosthetic device capable of preventing the onset ofinfections or capable of treating those present in the surgical site inwhich the prosthetic device itself is implanted.

Another object of the present invention is to provide a prostheticdevice that is both of first implant and revision.

A further object of the present invention is to provide a prostheticdevice with mechanical properties comparable to those of theconventional final prostheses.

In accordance with one aspect of the present invention, prostheticdevice is provided according to the present specification.

In accordance with another aspect of the present invention, a kit isprovided comprising a prosthetic device according to the presentspecification.

In accordance with a further aspect of the present invention a method isprovided for obtaining a prosthetic device according to the presentspecification.

The present specification refers to preferred and advantageousembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will beclearer from the detailed description of a preferred but not exclusiveembodiment of a prosthetic device, illustrated as a non-limiting examplein the enclosed drawing tables, in which:

FIG. 1 is a partially rear perspective view of a portion or of a versionof the prosthetic device according to the present invention;

FIG. 2 is a partially front perspective view of a portion or a versionof the prosthetic device according to the present invention;

FIG. 2a is a perspective view of a detail sectioned along the transversetrace plane IIa-IIa of FIG. 2;

FIG. 2b is a perspective view of a detail sectioned along the transversetrace plane IIb-IIb of FIG. 2;

FIG. 3 is a front portion of the portion or of the version of theprosthetic device of FIG. 2;

FIG. 4 is a longitudinal section view along the trace plane IV-IV ofFIG. 3;

FIG. 5 is a cross section view along the trace plane V-V of FIG. 4;

FIG. 6 is a cross section view along the trace plane VI-VI of FIG. 4;

FIG. 7 is a longitudinal section view of the portion or of the versionof the prosthetic device of FIG. 1 or 2, in which the fill materialthereof is visible;

FIG. 8 is a partially transparent perspective view of a tibial portionor version of the prosthetic device according to the present invention;

FIG. 9 is a side view of a diagram relative to the tibial portion orversion of the prosthetic device of FIG. 8:

FIG. 10a is a side section view of an acetabular portion or version ofthe prosthetic device according to the present invention;

FIG. 10b is a side section view of an acetabular portion or version ofthe prosthetic device of FIG. 10a ; and

FIG. 11 is a side section view of a further version of the acetabularportion or version of the prosthetic device of FIG. 10 b.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the enclosed figures, a prosthetic device according tothe present invention is overall indicated with reference number 1.

Such prosthetic device 1 comprises a permanent prosthesis, whether it isa first implant prosthesis or a so-called revision prosthesis, i.e.inserted following the implant of a spacer device in a two stagetreatment procedure.

Such prosthetic device 1 can be a hip prosthesis (such as the portionsillustrated in FIGS. 1 to 7, 10 a, 10 b and 11), a shoulder prosthesis,an elbow prosthesis, a knee prosthesis (such as the tibial portionsillustrated in FIGS. 8 and 9) or a bone prosthesis in general.

The prosthetic device 1 comprises a prosthetic body 2.

The prosthetic device 1 or the prosthetic body 2 comprises or can beadded with antibiotic or a medical substance, as will be betterdescribed hereinbelow in the present description.

The prosthetic body 2 comprises, in one version of the invention, atleast one tubular wall, said tubular wall having an outer surface 41 aswell as an inner surface 42 delimiting the inner cavity 5. In FIGS. 1 to7, as prosthetic body, a stem component 2 a of a hip prosthesis isdepicted, as a non-limiting example of the prosthetic device 1 accordingto the present invention. Generally, the prosthetic body 2 comprises awall which has an outer surface 41 and an inner surface 42 delimitingthe inner cavity 5.

When the prosthetic device according to the present invention comprisesa hip prosthesis, it can include a head component intended to beimplanted in the acetabular cup of a patient and a stem component 2 a,delimited by the tubular wall of the prosthetic body 2 and intended tobe implanted in the femur of a patient.

The stem component 2 a projects upward from the head component and haselongated shape with a first base end proximal to the head component aswell as a second tip end 4; the inner cavity 5 is delimited within thestem component 2 a so as to have a substantially elongated extensionaround the longitudinal extension axis L of the stem component 2 a, fromits first end to its second end 4.

In one version of the invention, the stem component 2 a has asubstantially longitudinal progression, along the longitudinal extensionaxis L, and has a tapered shape starting from the first base end up tothe second tip end 4. At the first base end, a neck portion 3 is presentadapted to come into contact with the head component.

The neck portion 3 is placed at the hip joint of the human body. Thesecond tip end 4, instead, is adapted to be inserted within themedullary canal of the femoral bone of the patient. The stem component 2a or the prosthetic device 1 or the prosthetic body 2 has, as statedabove, an inner cavity 5.

The inner cavity 5, in this version of the invention, has a shapesubstantially corresponding to that of the prosthetic device 1 or of theprosthetic body 2 at whose interior it is obtained.

According to the embodiment represented in the figures, the inner cavity5 of the stem component 2 a has a substantially longitudinal shape alongthe longitudinal axis L.

The inner cavity 5 of the stem component 2 a has a substantiallycontinuous shape, from the neck portion 3 to the second tip end 4 of thecomponent 2 a.

The size of the inner cavity 5 is reduced with respect to the overallsize of the prosthetic device 1, so as to not reduce or affect themechanical properties of the prosthetic device 1 according to thepresent invention.

Indeed, the prosthetic device can be positioned during use within a boneor joint site and it must be able to support the weight of the userand/or the movements tied to the area in which it is implanted.

With respect to a completely solid prosthetic device, e.g. a prosthesisof conventional type, therefore, the presence of the inner cavity 5 mustnot compromise the mechanical properties of the prosthetic deviceitself.

The prosthetic device 1 according to the present invention furthercomprises holes or ports 6.

Such holes or ports 6 are, according to one version of the invention,evenly distributed along the entire wall and/or the outer surface 41 ofthe prosthetic device 1.

In the enclosed figures, only some holes or ports 6 are present, withoutat all limiting the number or arrangement thereof.

The holes or ports 6 are formed transversely to the wall of theprosthetic body 2, so as to be extended from the inner surface 42 to theouter surface 41 thereof.

According to one version of the invention, the prosthetic device 1 has aplurality of holes or ports 6.

Such ports or holes 6 are adapted to place in communication the spacecorresponding to the inner cavity 5 with the space outside theprosthetic device 1 or with the bone tissue surrounding the prostheticdevice 1 during use.

In particular, such holes or ports 6 pass through the inner cavity 5 andthe space outside the prosthetic device 1 and hence pass through thewall of the prosthetic device 1 or pass from the outer surface 41 to theinner surface 42 thereof.

The size of the holes or ports 6 are such to allow the passage, in bothsenses, of liquids or gases, e.g. biological liquids, medicatedsubstances, etcetera.

The inner cavity 5, according to one version of the invention, isadapted to comprise, contain or house a filler material 7.

Therefore, in one version of the invention, the prosthetic device 1comprises a filler material 7, housed in the inner cavity 5.

The filler material 7 is in fluid, solid or solidifiable fluid form.

In one version of the invention, the filler material 7, when arrangedinside the inner cavity 5, is hardened. The filler material 7 isarranged at the entire extension of the inner cavity 5 and, possibly, ofthe holes or ports 6 so as to constitute a zone 7 a for the absorptionand subsequent elution of an antibiotic or medical substance or asolution comprising an antibiotic or medical substance.

In addition, in such a manner, the filler material 7 at least partiallyassists to re-establish the mechanical properties of a prosthetic deviceaccording to the invention, in a manner similar to that of a solidprosthesis of conventional type.

In particular, when the filler material 7 is arranged or penetrates intothe holes or ports 6, the continuity of the outer surface of theprosthetic body 2 is re-established.

In one version of the invention, the prosthetic device 1 comprises atleast one solution comprising an antibiotic or medical substance, suchsolution being absorbed by the filler material 7.

In one version of the invention, the filler material 7 comprises atleast one from among the following materials: acrylic resin, compositematerial comprising calcium phosphate or an inorganic salt, calciumsulphate, bioglass, polyvinyl alcohol, a mixture thereof. In a furtherversion of the invention, the filler material 7 comprises an absorbentmaterial, such as for example a thread of silk or cotton, or abiocompatible plant fiber or a woven or non-woven fabric, capable ofabsorbing and being soaked with a medical solution, e.g. antibiotic.

In a still further version of the invention, the filler material 7comprises a biocompatible semi-solid material comprising a medicalsubstance, such as an antibiotic. Such semisolid material can beinsoluble (for example bone cement) or soluble, e.g. animal collagen,sugars, cellulose, etcetera.

The main characteristic of such filler material 7 is that of havingcapillary capacity, i.e. of comprising, substantially for the entirevolume thereof, small channels with micrometric transverse size (i.e.considering the dimension perpendicular to that of greater extension ofthe small channel itself), capable of absorbing and eluting liquids viacapillarity.

Such small channels can be interconnected and they are preferablyinterconnected in one version of the invention.

In one version of the invention, the filler material 7 comprises anacrylic resin and an inorganic salt, such as PMMA(polymethylmethacrylate) and calcium phosphate or tri-calcium phosphate(TCP).

In one version of the invention, the average cross-section diameter ofsuch small channels is less than 100 microns.

In FIGS. 8 and 9, one version of the present invention is illustrated,in which the prosthetic device 1 or the prosthetic body 2 comprises atibial portion of a knee prosthesis. Such version has the samecharacteristics as that just described above, it only varies with regardto the shape, which is specific for the implant site in which it must bepositioned.

The prosthetic body 2 comprises at least one wall, said wall having anouter surface 41 as well as an inner surface 42 delimiting the innercavity 5. As prosthetic body, a stem component 2 b and a tibial platecomponent 20 of the tibial portion of a knee prosthesis are depicted, asnon-limiting example of the prosthetic device 1 according to the presentinvention.

The stem 2 b has a substantially tubular wall while the tibial platecomponent 20 has a substantially box-like wall.

The prosthetic body 2, in particular the tibial plate component 20, inone version of the invention illustrated as an example in FIG. 9, iscomposed of at least two parts: a first portion or shell 2 a and asecond portion or shell 2 c.

Such first portion or shell 2 a and second portion or shell 2 c comprisethe aforesaid wall which has an outer surface 41, an inner surface 42and delimits the inner cavity 5. In particular, in one version of theinvention, the first portion or shell 2 a comprises a semi-wall and asemi-cavity 5 of the prosthetic body 2, and analogously the secondportion or shell 2 c comprises a semi-wall and a semi-cavity 5 of theprosthetic body 2; at least the first portion or shell 2 a or at leastthe second portion or shell 2 c or both are hollow portions. Theircavity constitutes the inner cavity 5 of the prosthetic body 2.

Therefore, each of such first portion or shell 2 a and second portion orshell 2 c form a part of the prosthetic body 2 and, once joinedtogether, they constitute the entire prosthetic body 2 and the entirecavity 5 comprised therein.

As illustrated in FIG. 9, the second portion or shell 2 c also comprisesthe stem component 2 b.

The first portion or shell 2 a is joined with the second portion orshell 2 c by means of a respective peripheral edge 2 a 1 and 2 c 1thereof. In FIG. 9, such peripheral edges 2 a 1 and 2 c 1 lie along atransverse plane IX-IX.

The stem 2 b is adapted to be inserted in the tibial medullary canal, atthe knee joint. Such prosthetic device could also comprise a femoralportion of a knee prosthesis, not illustrated but configured in aconventional manner, or preferably having the same characteristics ofthe tibial portion described herein.

In one version of the invention, also the femoral portion could becomposed of a first portion or shell (e.g. condylar) and a secondportion or shell (e.g. of rotation), which, being hollow, delimit aninner cavity.

Also such portions can be joined by means of respective outer peripheraledges, made in their lateral wall, so as to constitute, once joined, theinner femoral portion of the prosthetic device according to the presentinvention.

The stem component 2 b protrudes from the tibial plate component 20, inparticular from the lower surface thereof, and has elongated shape witha first base end proximal to the tibial plate component 20 as well as asecond tip end 4 b, so as to have an extension substantially elongatedaround the longitudinal extension axis of the stem component 2 b, fromits first end to its second end 4 b.

The inner cavity 5 is delimited within the stem component 2 b and withinthe tibial plate component 20, in order to carry out an improvedfunction. In one version of the invention, the cavity 5 can be delimitedonly with one of said elements.

The stem component 2 b or the tibial plate component 20 or theprosthetic device 1 or the prosthetic body 2 has, as stated above, aninner cavity 5.

The inner cavity 5 has, in this version, a shape substantiallycorresponding to that of the prosthetic device 1 or of the prostheticbody 2 at whose interior it is obtained.

The inner cavity 5 of the stem component 2 b and of the tibial platecomponent 20 has, in one version of the invention, a substantiallycontinuous shape.

Also in this version, the prosthetic device 1 according to the presentinvention further comprises holes or ports 6, with configuration andarrangement analogous to the previously described embodiment.

In addition, the inner cavity 5 is adapted to contain or house a fillermaterial 7, which has the characteristics indicated in the presentdescription.

The prosthetic device 1 or the prosthetic body 2 can be made of abiologically compatible material, of the type implantable inside thehuman body, such as metal, e.g. steel or titanium, metal alloys, plasticor acrylic resins, polymer materials, etcetera. The material of theprosthetic device 1, in any case, must be able to ensure the necessarymechanical properties, for example for support of the weights and/or forwear resistance, adapted to perform the function of permanent boneprosthesis.

The prosthetic device or the prosthetic body 2 is massive, and in oneversion of the invention it does not have planes of junction between itscomponents, for example the stem 2 a and the neck portion 3 or betweenthe tibial plate component 20 and the stem 2 b, and is hollow.

In one version of the invention, also the prosthetic body 2 of thedevice relative to a femoral hip prosthesis can comprise a first portionor shell and a second portion or shell. Such portions, being hollow,delimit the cavity 5 at their interior, and once joined together theyconstitute the entire prosthetic body 2. In such version of theinvention, the first portion or shell and the second portion or shellmirror each other.

The filler material 7 comprises, in one version of the invention, anantibiotic or medical substance.

For example, the antibiotic is adapted to oppose an infection underwayin the implant zone of the prosthetic device 1 or to prevent the onsetof an infection.

In a further version of the invention, the filler material 7 is adaptedto absorb, due to the capillarity given by its small channels, asolution containing an antibiotic or medical substance or an antibioticor medical substance.

In addition, the presence of the small channels of the filler material 7and of the holes or ports 6 of the prosthetic device 1 allows theantibiotic or medical substance or the solution comprising the same,contained in the filler material 7, to be eluted or delivered outsidethe prosthetic device 1, i.e. towards the bone tissue or towards thejoint space of the implant site. The antibiotic substance or medicalsubstance exits from the prosthetic device 1 by means of the holes orports 6.

If the filler material 7 also comprises calcium or other inorganicsalts, together with the delivery of the antibiotic or the medicalsubstance, also such calcium or such salts or ions thereof can be elutedor delivered.

Such inorganic substances are beneficial for the surrounding bone tissuewith which they come into contact.

The filler material 7 (and at least partially, in some versions, thematerial of the prosthetic device 1) absorbs the antibiotic or medicalsubstance. Therefore, in one version of the invention, the fillermaterial 7 is absorbent.

According to a further version of the invention, the filler material 7is porous.

The inner cavity 5, and the filler material 7, therefore act as a tankfor the antibiotic or medical substance or for the solution containingthe same, which is then released by the spacer device 1 through theholes or ports 6.

In the exemplifying version illustrated in FIGS. 1-7, the stem component2 a is made of a single piece with the neck portion 3. This aspect istied to the need, for the prosthetic device 1, to sustain the stressesdue to the support of the user's weight. Specifically, in fact, the neckportion 3 is the maximum stress zone, in the case of a hip prosthesis.

As stated above, a hip prosthesis of conventional type comprises ahemispherical head adapted to articulate with the acetabular cup or theacetabulum of the hip.

Also such hemispherical head, not illustrated in the figures, can bemade according to the present invention, i.e. comprising an innercavity, this time with shape corresponding to that of the head, andhence at least partially hemispherical, adapted to contain the fillermaterial and thus the antibiotic or medical substance.

In order to allow the exit of the antibiotic or medical substance or ofthe solution containing the same, the head comprises holes or ports withsize such to not interfere with the rotation movement and/or partialtranslation of the head itself in its joint implant zone. Suchprosthetic device 1, due to its particular structure and to the fillermaterial 7 contained therein, allows having a greater exposure, in termsof time and/or of concentrations, to antibiotic or medical substance.Therefore, unlike what occurs for the prostheses of the prior art, it ispossible to cure an infection underway in the bone tissue relative tothe implant site, or to prevent the onset of a new infection.

Indeed, the delivery/elution of the antibiotic or medical substancelasts for at least one day.

In FIGS. 10a, 10b and 11, an acetabular version of the present inventionis illustrated, in which the prosthetic device 1 or the prosthetic body2 comprises an acetabular cup 50 or acetabular portion of a hipprosthesis.

The acetabular cup 50 has dome or hemispherical shape; it constitutesthe upper part of a total hip prosthesis.

The acetabular cup 50, during use, is inserted and/or fixed in theacetabular cavity or cup, at the pelvis of the patient.

Such version has the same characteristics as that just described above,but it varies with regard to shape, which is specific for the implantsite where it must be positioned.

The prosthetic body 2 comprises at least one wall, said wall having anouter surface 41 as well as an inner surface 42 delimiting the innercavity 5.

In particular, the outer surface 41 of the acetabular cup 50 is convexand adapted to come into contact with the bone of the patient; the innersurface 42 is concave, and adapted to be joined, possibly by means ofinterposition of a joint insert 60, with the head of the hip prosthesisconnected to the femoral component thereof.

The inner surface 42 delimits a joint cavity with hemispherical shape,substantially complementary to that of the prosthetic head of the hipprosthesis.

The thickness of the wall of the acetabular cup 50, delimited betweenthe outer surface 41 and the inner surface 42, houses the holes or ports6 and a plurality of cavities 5.

In particular, the holes or ports 6 have a configuration and arrangementanalogous to the previously described.

The cavities 5 have, in this version, a shape substantiallyhemispherical or in any case they correspond with a space at whoseinterior it is possible to house the filler material 7.

In particular, a cavity 5 is present at one hole or port 6, or a cavity5 is present at some holes or ports 6 close to each other.

In a further version of the invention, the inner cavity 5 has asubstantially continuous shape, corresponding to the inner surface 42 ofthe acetabular cup 50.

As stated above, the at least one inner cavity 5 is adapted to containor house a filler material 7, which has the characteristics indicated inthe present description.

Outside of the acetabular cup 50, at the bone tissue and at the outsideopening of the holes or ports 6, a zone 7 a is delimited for theabsorption and subsequent elution of an antibiotic or medical substanceor a solution comprising an antibiotic or medical substance, possiblycontained in the filler material 7.

At the inner surface 42 of the acetabular cup 50, a joint insert 60 canbe present. The joint insert 60 is an insert made of ceramic orpolyethylene which articulates with the head of the hip prosthesis.Indeed, such joint insert 60 ensures a smooth sliding surface withlimited friction, in order to facilitate the sliding of the prosthetichead and hence the movements of the hip joint of the patient.

When present, the joint insert 60, inserted in contact with the innersurface 42 of the acetabular cup 50, closes the at least one cavity 5from the inner side in a manner such that the zone 7 a for theabsorption and subsequent elution of an antibiotic or medical substanceor a solution comprising an antibiotic or medical substance is onlydirected towards the outside of the acetabular cup 50.

The present invention further refers to a kit comprising the abovedescribed prosthetic device 1 and the filler material 7.

Finally, the present invention refers to a method for obtaining aprosthetic device 1 according to the present invention, comprising thesteps of arranging a prosthetic device 1, suitable for being implantedin a bone or joint site of the human body, and arranging a fillermaterial 7.

Such step for arranging the prosthetic device 1 comprises, in oneversion of the invention, arranging a first portion or shell of theprosthetic body 2 and a second portion or shell of the prosthetic body2. Such first and second portion or shell delimit the inner cavity 5 ofthe prosthetic device 1 or each delimits a semi-cavity.

In such version, the first portion or shell is joined with the secondportion or shell in a manner so as to obtain a single prosthetic body 2that is internally hollow.

The joining of the first portion or shell to the second portion or shellcan occur via welding or melting or softening of the materials thatconstitute the prosthetic body 2.

The method then provides for inserting, for example by means ofinjection or positioning, the filler material 7 in the inner cavity 5 ofthe prosthetic device 1.

The filler material 7 can be inserted or positioned in the prostheticdevice 1 through an opening 30 or multiple openings 30 suitably arrangedtherein.

In the version in which the prosthetic device 1 is a hip prosthesis,such opening 30 is provided at the second tip end 4 of the stemcomponent 2 a.

When instead the prosthetic device is a tibial portion of a kneeprosthesis, such opening 30 is provided in the end of the stem 2 b,adapted to penetrate into the tibial medullary canal. Possibly, thefiller material 7 is allowed to harden, once inserted or positioned inthe aforesaid inner cavity 5.

Once the filler material 7 is inserted or positioned, the surgeon canimmerse the prosthetic device 1 within a solution comprising anantibiotic or medical substance, in a manner such that the same canpenetrate by means of the holes or ports 6 within the prosthetic deviceand then, via capillarity, within the filler material 7.

In one version of the invention, the filler material 7 is soaked withthe aforesaid solution.

In such a manner, once the prosthetic device 1 is implanted in the humanbody, the solution containing an antibiotic or medical substance will bereleased by the filler material 7 and can exit, always through the holesor ports 6, towards the surrounding bone tissue, where it will carry outits antibiotic or antimicrobial function.

An advantage conferred by the present invention is the fact that theantibiotic or medical substance is substantially delivered by the entiresurface of the prosthetic device in contact with the bone tissue or isin any case capable of reaching all the bone tissue in contact with theprosthetic device according to the present invention.

Studies conducted in the field have in fact revealed that the bonetissue absorbs, in a concentrated manner, all the antibiotic molecules(even only a few) that come into contact therewith. In such case, thequantity of antibiotic or medical substance locally reaches theeffective concentration for eradicating the infection.

For this reason, it is essential that the holes or ports 6 aresubstantially present over the entire outer surface of the prostheticdevice 1, in a manner such to be extended over the entire area ofcontact with the bone tissue and thus, if present, of the infection.

The given definition of “porous” element, present in the presentdescription, can be substituted with “semi-permeable”, without departingfrom the protective scope of the present invention.

The invention thus conceived is susceptible of numerous modificationsand variants, all falling within the scope of the inventive concept.

The characteristics presented for one version or embodiment can becombined with the characteristics of another version or embodiment,without departing from the protective scope of the present invention.

In addition, all details can be substituted with other technicallyequivalent elements. In practice, the materials used, as well as thecontingent shapes and sizes, can be of any type in accordance with therequirements, without departing from the protective scope of thefollowing claims.

The invention claimed is:
 1. A prosthetic device suitable for beingimplanted in a bone or joint site of the human body, comprising: aprosthetic body, wherein said prosthetic device comprises at least oneinner cavity, and through holes or ports extending from said at leastone inner cavity to an outer surface of said device and intended to putsaid at least one inner cavity in communication with the outer surfaceof the prosthetic device or with the bone tissue surrounding, in use,said prosthetic device, wherein the prosthetic body comprises a stemcomponent having a wall having an outer surface as well as an innersurface delimiting said at least one inner cavity, said stem componenthaving an elongated shape with a first base end proximal to a neckportion, and a second tip end, said at least one inner cavity beingdelimited within said stem component so as to present a substantiallyelongated development around an axis of longitudinal extension (L) ofsaid stem component from said first base end to said second tip end,wherein said through holes or ports are evenly distributed along anentire outer surface of the stem component from the first base end tothe second tip end, wherein said prosthetic device comprises at leastone filler material comprising a solidifiable fluid arranged andhardened inside at least one of said at least one inner cavity and saidholes or ports so as to constitute a zone for the absorption andsubsequent elution of an antibiotic or of a solution comprising saidantibiotic, wherein said filler material has small interconnectedchannels which have an average cross-section diameter lower than 100microns.
 2. The prosthetic device according to claim 1, wherein said atleast one inner cavity has a shape substantially corresponding to ashape of the prosthetic body or a hemispherical shape or delimits aspace suitable for accommodating the filler material.
 3. The prostheticdevice according to claim 1, wherein said prosthetic body is made of abiologically compatible material implantable in the human body.
 4. Theprosthetic device according to claim 1, comprising at least one openingfor access to said at least one inner cavity to insert the fillermaterial in the at least one inner cavity.
 5. The device according toclaim 4, wherein said opening is provided at said second tip end.
 6. Theprosthetic device according to claim 1, wherein said holes or ports arearranged transversely to said wall so as to extend from said innersurface to said outer surface.
 7. The prosthetic device according toclaim 6, comprising a tibial portion of a knee prosthesis and includinga tibial plate component and a stem, wherein said stem is intended to beimplanted in the medullary canal of a patient, wherein said tibial platecomponent and said stem are delimited by said wall, said stem componentprotruding from said tibial plate component, said stem component havingan elongated shape with a first base end proximal to said tibial platecomponent and a second tip end, said inner cavity being delimited bysaid stem component and/or within said tibial plate component so as tohave a development substantially corresponding to that of saidprosthetic device.
 8. The device according to claim 7, wherein saidopening is provided at said second tip end.
 9. The prosthetic deviceaccording to claim 6, comprising a hip prosthesis and including anacetabular cup, wherein said acetabular cup has a wall delimited by saidouter surface and by said inner surface, wherein said outer surface isconvex and said inner surface is concave, wherein said wall accommodatesin its thickness a plurality of cavities at said holes or ports.
 10. Thedevice according to claim 9, comprising a joint insert placed in contactwith said inner surface of said acetabular cup and suitable for closingfrom the inside said plurality of cavities.
 11. The prosthetic deviceaccording to claim 6, comprising a hip prosthesis and including a headcomponent intended to be implanted in the acetabulum of a patient, andwherein the stem component delimited by said wall is intended to beimplanted in the femur of a patient, said stem component protruding fromsaid head component.
 12. A kit for the implementation of a prostheticdevice comprising or able to be added with an antibiotic or a medicalsubstance, comprising a prosthetic device according to claim 1, and afiller material.
 13. The kit according to claim 12, wherein said fillermaterial is a fluid or a solid or a solidifiable fluid.
 14. The kitaccording to claim 12, wherein said filler material comprises at leastone among the following materials: acrylic resin, composite materialcomprising calcium phosphate or an inorganic salt, calcium sulphate,bioglass, polyvinyl alcohol, or an acrylic resin or PMMA and aninorganic salt or calcium phosphate or tri-calcium phosphate (TCP) or athread of silk or cotton, or a biocompatible vegetable fibre or a wovenor non-woven fabric, or a semi-solid biocompatible insoluble or solublematerial, or wherein said semi-solid insoluble material is bone cementor wherein said semi-solid soluble material is animal collagen, sugars,cellulose, etc., or a mixture thereof.
 15. The kit according to claim12, wherein said filler material is suitable for absorbing or gettingsoaked in an antibiotic or medical substance or a solution comprising anantibiotic or medical substance and for releasing it to the outside ofsaid prosthetic device by means of holes or ports present in saidprosthetic body.